J. Agric. Food Chem. 2004, 52, 8017−8020
8017
A Comparison of Carotenoid Content and Total Antioxidant Activity in Catsup from Several Commercial Sources in the United States BETTY K. ISHIDA*
AND
MARY H. CHAPMAN
Western Regional Research Center, U.S. Department of Agriculture, Agricultural Research Service, 800 Buchanan Street, Albany, California 94710
Samples of catsup from 13 commercial sources, representing at least 10 U.S. manufacturers, were analyzed for carotenoid content, antioxidant activity, and percentage solids. The solids content of these catsup brand samples varied from 26.31 to 38.06% solids. The lycopene content ranged from 59.42 to 183.36 µg, and total carotenoids were as high as 216.6 µg/g fresh weight, respectively. In addition, both hydrophilic and lipophilic antioxidant activities were measured using the Trolox equivalent antioxidant capacity (TEAC) assay. These measurements of samples of the various catsup brands ranged from 176.5 to 356.8 total TEAC units. KEYWORDS: Tomato; catsup; lycopene; carotenoid; Trolox equivalent antioxidant activity; solids
INTRODUCTION
Because of recent epidemiological findings that the consumption of tomatoes and tomato products is strongly correlated with a reduced risk of certain cancers (e.g., prostate, gastrointestinal, and epithelial cell) and cardiovascular disease (1-3), the antioxidant activity and, in particular, the carotenoid content of various tomato products are of interest. The protective effect of consuming tomato products has been attributed to lycopene, the major carotenoid in tomatoes. Lycopene is responsible for the red color of tomato fruit and generally represents more than 80% of its total carotenoid content (4, 5). It was shown to be the strongest biological quencher of singlet molecular oxygen (6) and, therefore, presumably the most effective in protecting against oxidative damage from free radicals. Catsup is a major form of tomato consumption in the United States and the Western world. In the United States, the population has become caught up in an increasingly busy lifestyle, which discourages time-consuming meal preparation at home. In addition, marketing is directed more and more toward children and teenagers. Therefore, fast food restaurants are becoming more and more appealing. The primary reason, however, for increased catsup consumption is a result of the increasing spread of American fast food restaurants throughout the world. In this country, catsup is available from many sources, including numerous commercial brands sold in supermarkets and grocery stores, health food stores, and fast food restaurants. These sources seemingly offer very similar products that are often hard to distinguish except by brand name. However, in addition to the standard dark red product, which varies in degrees * To whom correspondence should be addressed. Tel: 510-559-5726. Fax: 510-559-6166. E-mail:
[email protected].
of the depth of its red color, catsup is now available in various colors, without added salt, and with additional spices. Because of the difficulty in assessing the carotenoid content of catsup by appearance, its delivery of high lycopene content and antioxidant capacity, and general interest in the benefits of tomato products to consumer health, we investigated differences in several products that are commonly available to the public in the United States. MATERIALS AND METHODS Sources of Catsup. Catsup from 13 different commercial sources, representing at least 10 U.S. manufacturers, was purchased from major supermarkets, health food stores, and fast food restaurants for analysis. Samples of catsup were removed from unopened containers stored at room temperature until opened and then were stored in the dark at refrigerator temperatures at approximately 5 °C. (Carotenoid compositions and antioxidant activities were stable under these conditions.) The catsup manufacturers represented were major brands, store brands, organic food companies, and companies providing catsup to fast food restaurants in individual servings contained in plastic packets. Percentage Dry Weight (DW). Moisture contents and DWs were determined, using a model AVC-80 microwave moisture/solids analyzer (CEM Corporation, Mathews, NC). Samples of catsup were placed between two tared glass fiber pads and heated at 50% power for 4.5 min. The moisture content (or percent solids) was determined by the difference in weight after drying. Carotenoid Analyses. Carotenoids were extracted from catsup samples essentially as described by Ishida et al. (7, 8). Extracts containing carotenoid fractions were dried quickly under a stream of nitrogen and stored at -20 °C. Just before analysis, the dried extracts were dissolved in tetrahydrofuran. The lycopene content was determined in a Beckman model DU 640 spectrophotometer, measuring the absorbance at 470 nm and using a molar extinction coefficient in hexane of 3450. The carotenoid content was analyzed by injecting 25 µL aliquots into a Waters high-performance liquid chromatography (HPLC)
10.1021/jf040154o This article not subject to U.S. Copyright. Published 2004 by the American Chemical Society Published on Web 12/07/2004
8018
J. Agric. Food Chem., Vol. 52, No. 26, 2004
Ishida and Chapman
Table 1. Solids Contents of Commercial Brands of Catsup brand
% solids
brand
% solids
M4 (SD) M5 (SD) M6 (SD)
33.05 (0.16) 33.25 (0.37) 33.77 (0.29)
O3 (SD)
35.23 (0.34)
major brandsa M1 (SD)b M2 (SD) M3 (SD)
31.65 (0.97) 32.21 (0.54) 32.86 (0.16)
O1 (SD) O2 (SD)
26.31 (0.30) 29.83 (0.33)
S1 (SD)
32.52 (0.31)
S2 (SD)
32.84 (0.41)
F1 (SD)
fast food/vending machine 34.28 (1.30) F2 (SD)
38.06 (1.30)
organic brands
store brands
a M2, hot; M3 and 5, no salt; M4, nonred. b Standard deviation, samples analyzed in triplicate.
equipped with a model 2690 Separations Module, model 996 Photodiode Array Detector, and a C30 carotenoid column (Waters, Milford, MA) according to the method of Ishida et al. (7, 8). Lycopene recovery using this method was found to be 94.5%; recovery of an external standard echinenone was 92.1%. Total Antioxidant Activity. The total antioxidant activity of tomato catsups was determined by the 2,2′-azino-bis-(3-ethylbenzthioazoline6-sulfonic acid) (ABTS)/H2O2/horseradish peroxidase decoloration method (9, 10). In this method, ABTS radical cation was generated chemically, and the standard antioxidant or sample being analyzed was added, which resulted in the loss of the ABTS+, which was measured by the decrease in absorbance. We used this method to determine hydrophilic and lipophilic antioxidant activities (HAA and LAA) (11, 12) in catsup, expressed as Trolox equivalent antioxidant capacities (TEAC) (9-12). To obtain the lipophilic components, catsup samples were extracted, using the method of Ishida et al. (7, 8). Hydrophilic constituents were obtained in the water soluble methanol wash at the beginning of the carotenoid extraction procedure. RESULTS AND DISCUSSION
Percentage DW. Data obtained on percentage DW of catsup samples are shown in Table 1. Values ranged from 26.31 to 38.06%. Catsups are placed into categories of major brands (M), store brands (S), organic brands obtained from organic/health food stores (O), and a fast food chain restaurant or vending machine (F). All but one brand of catsup, an organic brand (O1), were 30% or higher in solids content. The brand of catsup having the lowest solids content was only 69% that of the catsup brand having the highest solids, which was a packaged catsup from a fast food vending machine (F1). Carotenoid Content. Figure 1 shows mean values of lycopene concentrations in the catsup samples tested. These values were based upon spectrophotometric measurements, which result in an overestimation of lycopene because of the presence of small amounts of other carotenoids whose absorption spectra, which do not have peaks at 470 nm, contribute to this measurement. These values ranged from 59.42 to 183.36 µg/g fresh weight (FW), a more than 3-fold range in concentration. Catsup brands categorized as organic were purchased at a health food store and were highest in lycopene content, even when calculations were made based upon DW, although their order of ranking changed somewhat. (We are reporting lycopene concentrations based on FW because they reflect relative amounts of lycopene as they are actually delivered to the consumer.) The catsup sample obtained from a fast food chain restaurant (F1) was the next highest (fourth) in lycopene content. The brand having the lowest lycopene content in terms of both FW and DW was obtained from a fast food vending machine
Figure 1. Lycopene content of samples from different brands of catsup. O, brands labeled “organic” obtained from organic health food stores; M, brands produced by major commercial companies; S, supermarket brands; and F, catsup samples from a fast food restaurant or vending machine. Error bars represent the standard deviation of the mean value obtained from four samples taken from each catsup.
(F2). These data are all in the same ranges as those reported in the literature (13-17). The predominant carotenoids detected in our catsup samples were trans-lycopene, phytofluene, phytoene, lutein, R- and β-carotene, and three or four cis-isomers of lycopene. Figure 2 shows a chromatogram obtained from HPLC analysis of the catsup sample having the largest number of different carotenoids. Tonucci et al. (14) measured, in addition, quantities of ζ-carotene, neurosporene, and lycopene-5,6-diol. Schierle et al. (15) reported 77-88% all-trans-lycopene in two catsups, as well as percentages of three cis-isomers. Our estimates of total carotenoid content of catsup samples, as well as lycopene contents analyzed in the present study, are shown in Table 2. Our data show that the all-trans-lycopene comprised 68.9-100% of the total carotenoids. Note once again that the catsup samples having the highest carotenoid contents were the organic brands, followed again by the catsup from a fast food restaurant (F1). The lowest in carotenoid content, however, was found in the one obtained from a fast food vending machine. Antioxidant Capacity. Compounds in tomatoes and tomato products having antioxidant capacities that are reported in the literature include lycopene (6, 18-20), ascorbic acid (vitamin C) (21-25), R-tocopherol (vitamin E) (22, 26), β-carotene (provitamin A) (19, 22, 25, 27), and phenolic compounds (includes flavonoids and hydroxycinnamic acids) (25, 28-31). Martinez-Valverde (31) identified ferulic and caffeic acids, but not quercetin and chlorogenic acid, as phenolic compounds that were significantly related to the antioxidant capacity of several commercial tomato varieties. The protective effect of many biological compounds against certain degenerative diseases, e.g., several types of cancers, cardiovascular diseases, cataracts, age-related macular degeneration, and oxidative stress dysfunctions, has been attributed to their antioxidant activity (17, 32, 33). This activity can protect biological systems against the potential dangers from processes or reactions that can cause excessive oxidative damage from free radicals (6, 27). As a measure of antioxidant capacity, we quantified both HAA and LAA in catsup samples. These values are depicted in Figure 3. According to our measurements, LAA accounts for most of the antioxidant activity of catsup and consists of the antioxidant activity resulting from lycopene and other lipophilic compounds extracted from the catsup. Arnao et al. (12) analyzed both HAA and LAA antioxidant activities in tomato, gazpacho, and seven vegetable soups. Their data showed
J. Agric. Food Chem., Vol. 52, No. 26, 2004
Carotenoid Content and Antioxidant Activity in Catsup
8019
Figure 2. HPLC chromatogram of carotenoids extracted from a catsup sample, showing peaks of separated compounds whose identities were determined by injected standard samples and/or measured absorption spectra. The catsup sample shown here contained the largest number of carotenoid peaks of all of the catsup brands examined. Table 2. Carotenoid Contents of Commercial Brands of Catsup brand
trans-lycopenea
other carotenoidsb major
% trans-lycopene
totalb
84.0 72.3 68.9 83.0 82.6 82.0
161.7 121.3 145.3 172.0 102.5 115.5
brandsc
M1 (SD)d M2 (SD) M3 (SD) M4 (SD) M5 (SD) M6 (SD)
135.79 (4.44) 88.30 (17.34) 100.09 (9.29) 142.76 (0.75) 102.53 (21.56) 94.67 (4.43)
O1 (SD) O2 (SD) O3 (SD)
167.19 (7.01) 183.36 (7.07) 172.10 (13.83)
organic brands 35.3 0 44.5
82.6 100 79.5
202.5 183.4 216.6
S1 (SD) S2 (SD)
100.48 (12.43) 124.12 (7.95)
store brands 4.4 36.9
95.8 77.1
104.9 161.0
F1 (SD) F2 (SD)
fast food/vending machine 145.62 (7.79) 36.5 59.42 (2.21) ND
80.0 59.4
182.1 ND
25.9 33.0 45.2 29.2 NDe 20.8
a µg lycopene/g FW. b µg carotenoids/g FW, only one analysis. c M2, hot; M3 and 5, no salt; M4, nonred. d Standard deviation, samples analyzed in triplicate. e No data.
that in tomato soup, LAA represented only about one-fifth of the total antioxidant activity. Of that fraction, the relative antioxidant activity of lycopene plus β-carotene contributed onethird of the LAA. Therefore, the combination of HAA and the major carotenoid content in tomato soup represented 87% of the total antioxidant activity. Ascorbic acid contributed 35% of the HAA. The other two soups had lower HAAs (gazpacho about 63% and seven vegetable soup 43% that of tomato soup). Our data on LAA and HAA are expressed in Figure 3 as TEAC (9, 10, 12, 34). LAA values ranged from 79.5 (M2) to 201 (O3) TEACs and, as expected, are higher values than those obtained in soups by Arnao et al. (12). However, in contrast to tomato soup, which derived about 20% of its antioxidant activity from LAA, the LAA contribution in catsup samples ranged from 37.9 to 59.9% of the total antioxidant activity. These data do not necessarily reflect lycopene content in the catsup samples,
Figure 3. Antioxidant activity of samples from different catsup brands, showing contributions of LAA from lycopene (clear areas), without lycopene (striped areas), and HAA (solid areas). O, brands labeled “organic” obtained from organic health food stores; M, brands produced by major commercial companies; S, supermarket brands; and F, catsup samples from a fast food restaurant or vending machine. The values shown represent the mean obtained from three samples taken from each catsup.
although one might expect that the major contribution to LAA would be that from lycopene. However, the percentage of lycopene contributing to LAA varied from 13.7 (M6) to 51.2% (F1). This percentage was calculated based on the relative antioxidant activity of trans-lycopene as compared to Trolox, which was determined by Bohm et al. (10) to be 2.5. The three brands of catsup having the highest total antioxidant capacities were again the organic brands, but those deriving the greatest relative contribution of lycopene to LAA were F1, O2, and M4, having 51.2, 42.4, and 40.6% contributions from lycopene, respectively. HAA values obtained in our analyses of catsup samples varied from 92 (F1) to 239 (O1) TEACs. The catsup sample having the highest HAA again was an organic brand (O1), but a store brand (S1) had the second highest HAA, which was only 61.5% that of O1, followed by S2, O2, and O3, which were almost identical in HAA values (56.4-56.9% of O1). Tomato catsup is an excellent source of lycopene, carotenoids, and antioxidant compounds. A good estimate of lycopene
8020
J. Agric. Food Chem., Vol. 52, No. 26, 2004
content can be made by the dark red appearance of the product. The organic brands had a much deeper red color than the other brands examined. Samples of catsup produced by organic food companies were highest in lycopene and total carotenoid contents, total antioxidant activity, and LAA. In addition, two of the three organic brands had the highest HAA, and the third ranked number four. The catsup brand having the lowest solids content had the highest total antioxidant activity and the highest HAA. This was an organic brand (O1). It ranked third highest in lycopene content and fourth highest in LAA value. Two of the organic catsup brands had the lowest solids content. Therefore, solids content is not a good indicator of the nutritional value of the catsup. ACKNOWLEDGMENT
We thank Glenn E. Bartley, Qiming Shao, and Gary R. Takeoka for reviewing our manuscript and providing helpful suggestions. LITERATURE CITED (1) Giovannucci, E.; Ascherio, A.; Rimm, E. B.; Stampfer, M. J.; Colditz, G. A.; Willett, W. C. Intake of carotenoids and retinol in relation to risk of prostate cancer. J. Natl. Cancer Inst. 1995, 77, 1767-1776. (2) Clinton, S. K.; Emenhiser, C.; Schwartz, S. J.; Bostwick, D. G.; Williams, A. W.; Moore, B. J.; Erdman, J. W., Jr. Cis-trans lycopene isomers, carotenoids, and retinol in the human prostate. Cancer Epidemiol. Biomarkers PreV. 1996, 5, 823-833. (3) Giovannucci, E. Tomatoes, tomato-based products, lycopene, and cancer. Review of the epidemiologic literature. J. Natl. Cancer Inst. 1999, 91, 317-331. (4) Koskitalo, L. N.; Orm, D. P. Effects of sub-optimal ripening temperatures on the color quality and pigment composition of tomato fruit. J. Food Sci. 1972, 35, 56-59. (5) Sharma, S. K.; Le Maguer, M. Lycopene in tomatoes. Ital. Food Sci. 1996, 2, 107-113. (6) Di Mascio, P.; Kaiser, S.; Sies, H. Lycopene as the most efficient biological carotenoid singlet oxygen quencher. Arch. Biochem. Biophys. 1989, 274, 532-538. (7) Ishida, B. K.; Ma, J.; Chan, B. A simple, rapid method for HPLC analysis of lycopene isomers. Phytochem. Anal. 2001, 12, 194198. (8) Ishida, B. K.; Ma, J. C.; Chan, B. G.; Bartley, G. E.; Grossman, J. N. A modified method for simple, rapid HPLC analysis of lycopene isomers. Acta Hortic. 2001, 542, 235-242. (9) Miller, N. J.; Sampson, J.; Candeias, L. P.; Bramley, P. M.; RiceEvans, C. A. Antioxidant activities of carotenes and xanthophylls. FEBS Lett. 1996, 384, 240-242. (10) Bohm, V.; Puspitasari-Nienaber, N. L.; Ferruzzi, M. G.; Schwartz, S. J. Trolox equivalent antioxidant capacity of different geometrical isomers of R-carotene, β-carotene, lycopene, and zeaxanthin. J. Agric. Food Chem. 2002, 50, 221-226. (11) Cano, A.; Acosta, M.; Arnao, M. B. A method to measure antioxidant activity in organic media: Application to lipophilic vitamins. Redox Rep. 2000, 5, 365-370. (12) Arnao, M. B.; Cano, A.; Acosta, M. The hydrophilic and lipophilic contribution to total antioxidant activity. Food Chem. 2001, 73, 239-244. (13) Beerh, O. P.; Siddappa, G. S. A rapid spectrophotometric method for the detection and estimation of adulterants in tomato ketchup. Food Technol. 1959, July, 414-418. (14) Tonucci, L. H.; Holden, J. M.; Beecher, G. R.; Khachik, F.; Davis, C. S.; Mulokozi, G. Carotenoid content of thermally processed tomato-based food products. J. Agric. Food Chem. 1995, 43, 579-586.
Ishida and Chapman (15) Schierle, J.; Bretzel, W.; Buhler, I.; Faccin, N.; Hess, D.; Steiner, K.; Schuelp, W. Content and isomeric ratio of lycopene in food and human blood plasma. Food Chem. 1996, 59, 459-465. (16) Nguyen, M. L.; Schwartz, S. J. Lycopene stability during food processing. Proc. Soc. Exp. Biol. Med. 1998, 218, 101-105. (17) Rao, A. V.; Agarwal, S. Role of lycopene as antioxidant carotenoid in the prevention of chronic diseases: A review. Nutr. Res. 1999, 19, 305-323. (18) Palozza, P.; Krinsky, J. I. Antioxidant effects of carotenoids in vivo and in vitro: An overview. Methods Enzymol. 1992, 213, 403-420. (19) Oshima, S.; Ojima, F.; Sakamoto, H.; Ishiguro, Y.; Terao, J. Supplementation with carotenoids inhibits singlet oxygenmediated oxidation of human plasma low-density lipoprotein. J. Agric. Food Chem. 1996, 44, 2306-2309. (20) Woodall, A. A.; Lee, S. W.; Weesie, R. J.; Jackson, M. J.; Britton, G. Oxidation of carotenoid by free radicals: relationship between structure and reactivity. Biochim. Biophys. Acta 1997, 1336, 3342. (21) Davies, J. N.; Hobson, G. E. The constituents of tomato fruits The influence of environment, nutrition, and genotype. Crit. ReV. Food Sci. Nutr. 1981, 15, 205-279. (22) Abushita, A. A.; Daood, H. G.; Biacs, P. A. Change in carotenoids and antioxidant vitamins in tomato as a function of varietal and technological factors. J. Agric. Food Chem. 2000, 48, 2075-2081. (23) Abushita, A. A.; Hebshi, E. A.; Daood, H. G.; Biacs, P. A. Determination of antioxidant vitamins in tomatoes. Food Chem. 1997, 60, 207-212. (24) De Serrano, J. Q.; De Gonzales, L.; Solomons, N. W. The partition of ascorbic acid and dehydroascorbic acid in vitamin C containing Guatemalan foods. Food Chem. 1993, 47, 87-92. (25) Giovanelli, G.; Lavelli, V.; Peri, C.; Nobili, S. Variation in antioxidant components of tomato during vine and post-harvest ripening. J. Sci. Food Agric. 1999, 79, 1583-1588. (26) Vatassery, G. T.; Smith, W. E. Determination of a-tocopherol quinone (vitamin E-quinone) in human serum, platelets and red cell membrane samples. Anal. Chem. 1987, 167, 411-417. (27) Burton, G. W.; Ingold, K. U. β-Carotene: An unusual type of lipid antioxidant. Science 1984, 224, 569-573. (28) Hermann, K. Flavonols and flavones in food plants: A review. J. Food Technol. 1976, 11, 433-448. (29) Fleuriet, A.; Macheix, J.-J. Tissue compartmentation of phenylpropanoid metabolism in tomatoes during growth and maturation. Phytochemistry 1985, 24, 929-932. (30) Hertog, M. G. L.; Hollman, P. C. H.; Katan, M. B. Content of potentially anticarcinogenic flavonoids in 28 vegetables and 9 fruits commonly consumed in The Netherlands. J. Agric. Food Chem. 1992, 40, 2379-2383. (31) Martinez-Valverde, I.; Periago, M. J.; Provan, G.; Chesson, A. Phenolic compounds, lycopene and antioxidant activity in commercial varieties of tomato (Lycopersicum esculentum). J. Sci. Food Agric. 2002, 82, 323-330. (32) Gale, C. R.; Hall, N. F.; Phillips, C. I.; Martyn, C. M. Plasma antioxidant vitamins and carotenoids and age-related cataract. Ophthalmology 2001, 108, 1992-1998. (33) Simonelli, F.; Zarrilli, F.; Mazzeo, S.; Verde, V.; Romano, N.; Savoia, M.; Testa, F.; Vitale, D. F.; Rinaldi, M.; Sacchetti, L. Serum oxidative and antioxidant parameters in a group of Italian patients with age-related maculopathy. Clin. Chim. Acta 2002, 320, 111-115. (34) Pelligrini, N.; Visioli, F.; Buratti, S.; Brighenti, F. Direct analysis of total antioxidant activity of olive oil and studies on the influence of heating. J. Agric. Food Chem. 2001, 49, 25322538. Received for review March 24, 2004. Accepted October 16, 2004.
JF040154O
